Hi. 1992 Accord wagon with 224k on it. Been having the transmission problem where D4 stays lit and seems to only be staying in 3rd gear. I found the fried capacitor in the TCU and replaced/re-soldered.

Now, D4 light will go out, but after some time so it has me concerned. When I turn the key a half turn, the D4 light will go out either A. after about ten seconds B. right away if I recently turned the key

When it does go out after ten seconds, I hear the same exact sound as when you press the brake - hear the little clicking sound in the gear selector handle. In other words, after about 10 seconds of the key half turned, I hear a clicking sound at the gear selector and then D4 will go out, not immediately after you hear the fuel pump do it's thing like it should.

Any suggestions would be greatly appreciated!

 

Okay after about 5 hours later, D4 light won't go off at all. When key is half turned, I can shift from P to any gear without pressing the brake....could it be the brake switch????

 

I'd look at the brake light switch if your brake lights stayed on all the time. From your description, it sound like this is TCU or maybe ECU related.

The D4 light staying on means the transmission computer is detecting a problem. You can look at the common diy thread on top of the gen tech help forum. It has a thread on checking engine codes that applies to transmission codes.

If you had a fried cap on your TCU board, chances are something else fried. Search the web to find common failures points of the early 90s TCUs (like specific resistors, caps, etc..)